Impact of RAN Virtualization on Fronthaul Latency Budget: An Experimental Evaluation

TL;DR

This paper experimentally evaluates how RAN virtualization affects fronthaul latency in 5G networks, showing that virtualization can reduce latency budgets and that latency requirements vary with bandwidth and user load.

Contribution

It provides empirical data on fronthaul latency impacts of virtualization in 5G RAN, specifically for the Option 7-1 split, using the ARNO-5G testbed.

Findings

Fronthaul latency requirements are about 250 microseconds for Option 7-1.

Latency requirements vary with radio channel bandwidth.

Virtualization further decreases the latency budget.

Abstract

In 3GPP the architecture of a New Radio Access Network (New RAN) has been defined where the evolved NodeB (eNB) functions can be split between a Distributed Unit (DU) and Central Unit (CU). Furthermore, in the virtual RAN (VRAN) approach, such functions can be virtualized (e.g., in simple terms, deployed in virtual machines). Based on the split type, different performance in terms of capacity and latency are requested to the network (i.e., fronthaul) connecting DU and CU. This study experimentally evaluates, in the 5G segment of the Advanced Research on NetwOrking (ARNO) testbed (ARNO-5G), the fronthaul latency requirements specified by Standard Developing Organizations (SDO) (3GPP in this specific case). Moreover it evaluates how much virtualization impacts the fronthaul latency budget for the the Option 7-1 functional split. The obtained results show that, in the considered Option 7-1 functional split, the fronthaul latency requirements are about 250us but they depend on the radio channel bandwidth and the number of the connected UEs. Finally virtualization further decreases the latency budget.